Saturday 18 April 2020

REPAIR / SERVICING TV DEXP F32B7000B

Technical description and composition of the DEXP F32B7000B TV, type of panel and applicable modules. The composition of the modules.
DEXP LED
Model: F32B7000B
Chassis / Version: TP.S512.PB83
Panel: BOEI320WU1
LED backlight: GC32D09-ZC14 F-05
T-CON: HV320FHB-N00 47-6021049
LED driver (backlight): integrated into PSU
PWM LED driver: SN510P
Power Supply (PSU): integrated into MainBoard
PWM Power: PWM SOT23-6
MainBoard: TP.S512.PB83
IC MainBoard: CPU: S2T512, SPI Flash: 25Q64, Sound: TPA3110LD2, RT9108NB
Tuner: R840 (Rafael Micro)
Appearance
DEXP F32B7000B
General repair guidelines for TV LCD LED
Possible malfunctions
- The DEXP F32B7000B TV does not turn on, does not respond to the remote control and the control panel buttons, does not light up or blink indicators.
In such cases, the common power source, the AC / DC voltage converter, which is combined with the elements of the main board TP.S512.PB83, is often faulty. Then it is necessary to measure its output voltages and, in case of their complete or partial absence, it is necessary to check the serviceability of power switches and rectifier diodes of the converters for a possible short circuit.
In case of breakdowns of semiconductors in secondary circuits, the converter can usually work abnormally in the short circuit mode, and during short circuit in the power elements of the primary circuit, the mains fuse often breaks.
The breakdown of Mos-Fet keys used in pulsed sources is often caused by malfunctions of other elements, for example, in the power supply circuit of a PWM controller, in frequency-setting or damping circuits, as well as in Negative Stabilization Feedback. PWM SOT23-6 PWM chips are usually checked by replacing with new ones, or obviously working.
- There is no image, there is sound, it responds to the remote control. Or the image may appear for a second when turned on and immediately disappears.
In such cases, the most likely malfunction of the LED backlight elements. The reason for this may be a break in the LED circuit, or a problem in stabilizing their power supply.
To check the health in the LED circuit, it is better to use a current source with a maximum voltage of 200V. We do not recommend using any voltage sources for this purpose. You can check each LED individually with a simple Chinese multimeter (powered by 9 volts) in the P-N-junction test mode. If you connect the red probe of the multimeter to the anode of the LED, and the black to its cathode, then the 3-volt LED will light up slightly, and in the opposite direction you can detect the transition of the emergency zener diode. A zener diode PN junction indirectly indicates a LED-a
- The TV does not enter the operating mode, does not respond to the remote control. The indicator on the front panel lights constantly or blinks.
Repair or diagnostics of the TP.S512.PB83 motherboard should begin by checking the stabilizers and power converters needed to power the microcircuits and matrix. If necessary, update or replace the software (software). In cases of complex repairs of MB (SSB) and in the presence of the necessary skills and equipment, sometimes it may be necessary to replace its CPU chips: S2T512, SPI Flash: 25Q64, Sound: TPA3110LD2, RT9108NB and other possible faulty components. Malfunctions associated with the application of BGA soldering technologies are usually easily diagnosed by the heating method.
In the absence of tuning to the channels of terrestrial or cable television, you should make sure that the software is correct and that the voltage ratings at the terminals of the R840 tuner (Rafael Micro) are in accordance with the ratings. It is also necessary to check the presence of tuner data exchange pulses with the processor via the oscilloscope I2C.
We advise owners of the F32B7000B TV to repair only qualified specialists with the necessary work experience! Self-repair attempts without the appropriate knowledge and skills can lead to irreversible negative consequences.



The appearance of MainBoard TP.S512.PB83 is shown in the figure below:
TP.S512.PB83
TP.S512.PB83 can be used in TVs:
AKAI LEA-39V51P (Panel LC390TA2A 902-P05-390H ), DEXP 40A7000 (Panel C400F13-E2-C), DEXP F39B7100E (Panel T390HVN04.0 CX390DLEDM), DEXP H32B7000C (Panel T320XVN02.9 C320X14-E2-A), DEXP F42B7000ED (Panel CX420DLEDM), DEXP F32C7000B (Panel BOEI320WU1), DEXP F32C7100B/W F32C7100 (Panel BOEI320WU1), DEXP 32A7000 (Panel BOEI320WU1), DEXP 42A7000 (Panel CX420DLEDM), DEXP F32B7000B (Panel BOEI320WU1), DEXP H39D7000E (Panel CX390DLEDM), DEXP F40B7000C (Panel C400F13-E2-C), DEXP H32B3200CD (Panel HV320WX2-201), HAIER LE28F6000T (Panel A275HD1A01-2 / LVW280CSDO E2 V2), HAIER LE32F6000T (Panel ST3151A05-8 LVW320CSDX E13 V2), MYSTERY MTV-4025LT2 (Panel CX400DLEDM), SHIVAKI STV-32LED13 (Panel SV320SHD PDL320TU2A X41), SHIVAKI STV-42LED16 (Panel V420HJ-P01), SHIVAKI STV-32LED14 (Panel CX315DLEDM AJ32TO3), SHIVAKI STV-40LED13W (Panel V400HJ6PE1-C2), SHIVAKI STV-32LED15 (Panel HV320WHB-N80), SUPRA STV-LC32T440WL (Panel C320X14-E13-H), SUPRA STV-LC32T900WL (Panel LC320TU3A), SUPRA STV-LC40T900FL (Panel 1080p Full HD 1920x1080), THOMSON T32D15DH-01B (Panel LVW320CSDX E13 V30), THOMSON T28D15DH-01B (Panel LVW280CSDE E3 V5), THOMSON T32D16DH-01W T32D16DH (Panel LVW320CSDX E19 V28), THOMSON T43D16SF-01B T43D16SF (Panel LVF430LGDO E2 V18).
Main features of the DEXP F32B7000B device:
Installed matrix (LED-panel) BOEI320WU1.
The matrix control uses the Timing Controller (T-CON) HV320FHB-N00.
To power the backlight LEDs, a converter is used, combined with a power supply, controlled by the SN510P PWM controller.
The power module is combined with the MainBoard and is made according to the flyback AC / DC voltage converter circuit using PWM SOT23-6 microcircuits.
MainBoard - the main board (motherboard) is a TP.S512.PB83 module, using CPU chips: S2T512, SPI Flash: 25Q64, Sound: TPA3110LD2, RT9108NB and others.
The R840 tuner (Rafael Micro) provides TV reception and channel tuning.